Single-component moisture-curable coatings based on n-substituted urea polymers with extended chains and terminal alkoxysilanes

ABSTRACT

Moisture-curable single-component (1K) coatings based on N-substituted urea polymers with extended chains and terminal alkoxysilane groups. The coatings are highly flexible, are gloss retentive, provide fast tack-free and dry-through times, provide high solvent resistance, and provide excellent exterior color stability to sunlight. The coatings can be formulated to produce high-gloss, semi-gloss and low-gloss finishes, and thus have application as both commercial and military coatings.

PRIORITY CLAIM

The present application is a continuing application of U.S. applicationSer. No. 14/187,568, filed on Feb. 24, 2014 by Erick B. Iezzi, entitled“SINGLE-COMPONENT MOISTURE-CURABLE COATINGS BASED ON N-SUBSTITUTED UREAPOLYMERS WITH EXTENDED CHAINS AND TERMINAL ALKOXYSILANES,” which claimedthe benefit of U.S. Provisional Application No. 61/781,719, filed onMar. 14, 2013 by Erick B. Iezzi, entitled “IMPROVED FLEXIBILITY, GLOSSRETENTION AND ADHESION OF SINGLE-COMPONENT TOPSIDE COATINGS BASED ONN-SUBSTITUTED UREAS WITH TERMINAL ALKOXYSILANES AND SECONDARY DIAMINELINKAGES,” the entire contents of each are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to moisture-curable single-component (1K)topcoat coatings.

2. Description of the Prior Art

The U.S. Navy's predominant topside coatings are haze gray semi-glosssilicone alkyds. These coatings have been used on the topsides(freeboard and superstructure) of surface ships by the Navy since theearly 1960s. Silicone alkyd coatings are considered “user friendly” inthat they are single-component (all-in-one can) paints that have anindefinite pot-life in a closed can, have been reformulated to maintaincompliance with volatile organic compound (VOC) limits, and will cureeven under the most adverse conditions. Unfortunately, theseuser-friendly paints have several inherent limitations, which includecolor fading, chalking, loss of gloss, limited resistance to shipboardhydrocarbons, and limited surface hardness that makes running rust andsoot staining extremely difficult to remove. In addition, peeling,cracking and delamination of cured silicone alkyds can often result dueto application over inadequately prepared surfaces.

Silicone alkyd coatings can be formulated as single-component (1K)systems because they contain unsaturated fatty acid groups thatcrosslink in the presence of atmospheric oxygen. The coatings do notbegin to cure until they are applied to a surface and the solventevaporates, thereby possessing essentially a limitless pot-life in aclosed can. For Navy ships, silicone alkyd topside coatings arespecified as a Haze Gray color with a semi-gloss finish, are availablein a variety of volatile organic compound (VOC) levels (e.g., 340 g/L,250 g/L), and have a service-life of approximately 6-12 months.Frequently, silicone alkyd coatings need to be touched-up or repaired(e.g., via roller or brush), yet this mundane task would not be requiredif silicone alkyd coatings did not easily fade, discolor,peel/delaminate or stain within a few months after application. A singleapplication of silicone alkyd is specified at 2-5 mils dry filmthickness (DFT); however, due to the constant over-coating formaintenance, it is not uncommon for surfaces to possess greater than 50mils of topside coating.

Although Navy surface ships utilize silicone alkyd topcoats, themajority of topcoats used by the Navy are polyurethanes. Polyurethanesare formed by reaction of an isocyanate-functional material with ahydroxyl-functional material (e.g., polyester polyol or water), and areused to provide protective camouflage, exterior color stability,flexibility, chemical warfare agent resistance, hydrocarbon resistanceand chemical resistance. Polyurethane topcoats can be two-componentsystems or single-component systems. Polyurethane topcoats contain toxicisocyanates that can cause serious health issues for both coatingapplicators and the environment, and non-isocyanate alternatives thatoffer equal or greater performance are of high interest. Furthermore,two-component coatings require the mixing of components beforeapplication, which can result in insufficient cure times, reducedhardness, poor adhesion, and poor appearance if applicators do not mixthe materials correctly. Two-component coatings also have a limitedpot-life, which is an issue for individuals performing touch-up andrepair applications. For these reasons, single-component coatings arefavored over two-component systems.

Polysiloxane-based coatings have an inherent durability advantage overtraditional organic-based materials due to the presence ofsilicon-oxygen bonds. The Si—O bond, which has a bond enthalpy of 110kcal/mol, is stronger than the carbon-hydrogen (99 kcal/mol) andcarbon-carbon (83 kcal; mol) bonds found in organic coatings, therebyleading to an increase in thermal stability and resistance to oxidativedegradation by sunlight. Polysiloxanes, like many silicon-basedmaterials, are relatively non-toxic to humans, especially when comparedto the health issues associated with isocyanate-containing materials.

Two-component (2K) polysiloxane coatings are based on materials thatcontain both reactive organic groups and moisture-curable alkoxysilanegroups. These coatings are often referred to as “hybrid cure coatings,”where one portion of the coating is crosslinked by the ambient reactionbetween organic groups, such as amines and epoxies, while the otherportion forms a siloxane network via moisture hydrolysis of thealkoxysilane groups and condensation of the resulting silanols. Thesecoatings offer good exterior durability, hardness, chemical resistance,and direct-to-metal adhesion. However, they can suffer fromphotooxidation and yellowing due to the presence of amines, whichaffects the long-term color and gloss stability of these coatings.Similar to two-component polyurethanes, these materials suffer from poorapplication appearance and performance if not mixed correctly byapplicators, not to mention the limited pot-life and waste associatedwith a two-component system.

Single-component polysiloxane coatings are traditionally based onacrylic-silane polymers. These polymers are manufactured via radicalpolymerization of gamma-methacryloxypropyltrimethoxysilane with methylmethacrylate, hexyl acrylate or other organic monomers to form linearcopolymers with pendant alkoxysilane groups. The copolymers are high inmolecular weight and require significant quantities of solvent(s) tosolubilize the large polymer chains, thus making it difficult togenerate low VOC coatings. The pendant alkoxysilane groups are the onlyreactive functionalities on the copolymer, which enables the coating tobe cured via moisture hydrolysis and condensation. Single-componentcoatings based on these polymers are available on the commercial marketfrom several manufacturers, although they are not without theirdrawbacks. For instance, these coatings are slow to hydrolyze andcrosslink (cure) at room temperature when not exposed to high humidityenvironments, and they display poor chemical resistance when not fullycured due to the low crosslink density within the coating. These issuesresult because the acrylic-silane copolymers in the coating containpendent propyltrialkoxysilane groups that are inherently slow tohydrolyze and limited in quantity when compared to the non-reactivegroups in the copolymer backbone. Acrylic-silane binders often possessglass transition temperatures (Tgs) above room temperature in order toprovide fast dry-to-touch times (e.g., 1-3 hours), even though thecrosslinking reaction between polymers is slow to occur.

Single-component moisture-curable coating compositions were disclosed inU.S. Pat. No. 6,288,198. These coatings are based on aliphaticpolyisocyanate-aminosilane adducts, where greater than 70% of theisocyanate groups are reacted with an aminosilane, which is thencombined with a hydrolysable silane to form a hybrid sol-gel coating. Itis stated that these sol-gel coatings provide hard, abrasion-resistantand solvent-resistant surfaces, which is expected for highly-crosslinkedcoatings, especially those that contain small hydrolyzable silanes.However, the reported flexibility is only a 90 degree bend, not a 180degree bend, which is the norm when referring to a highly flexiblecoating. Furthermore, the preferred coating dry film thickness is only2-30 microns, which is significantly less than what is utilized for mostcommercial and military coatings. An additional drawback to thesecoating compositions are that the high content of moisture-curablesilane groups within the coatings leads to a continual reduction ingloss over time as the coating post-cures with moisture.

Single-component moisture-curable coatings were also disclosed in U.S.Pat. No. 8,133,964, and are based on similar aliphaticpolyisocyanate-aminosilane adducts as those discussed above (paragraph[0009]). However, these adducts are formed by reacting polyisocyanateswith 2:1 or 1:2 ratios of N-substituted aminosilanes and di-substitutedmono-functional amines. Reactive diluents, such as hydrolyzable silanesor polysiloxanes could also be utilized. The di-substitutedmono-functional amines reduced the amount of hydrolysable silane groupson the polyisocyanate-aminosilane adduct, but the overall highconcentration of moisture-curable silane groups in the coating yieldedtopcoats with only slightly better flexibility than coatings reported inU.S. Pat. No. 6,288,198. The coatings still provided good solventresistance, high hardness and low VOCs. Additional drawbacks of thesecoatings are that the high content of moisture-curable groups leads to acontinual reduction in gloss over time as the coatings post-cure withmoisture, and that the use of the di-substituted mono-functional aminesresults in slow tack-free and dry-through times for the coatings.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to moisture-curable single-componentcoatings that are highly flexible, are gloss retentive, provide fasttack-free and dry-through times, provide good adhesion, are highlyresistant to solvents, and offer excellent exterior color stability tosunlight. The solution is provided by synthesizing N-substituted ureapolymers with extended chains and terminal alkoxysilane groups, thenformulating into moisture-curable single-component coatings. The coatingformulations can also comprise reactive diluents, pigments, fillers,solvents, additives and a catalyst. These single-component coatings canbe applied over a substrate via spray, brush or roll applicationmethods.

The single-component coatings of the present invention provide greaterexterior stability, adhesion, solvent resistance, flexibility and lowerVOC content than the silicone alkyd topside coatings currently utilizedon Navy ships. These coatings are also isocyanate-free, in that theN-substituted urea polymers with extended chains and terminalalkoxysilanes, including the reactive diluents and additives, contain nounreacted isocyanate groups. These coatings can be formulated to providehigh-gloss, semi-gloss and low-gloss finish coatings, and thus haveapplication as coatings for use on commercial and military assets (e.g.,ships, aircraft, ground vehicles and submarines).

The high flexibility of the herein coatings result from N-substitutedurea polymers with extended chains and terminal alkoxysilanes that aresynthesized utilizing aliphatic or cycloaliphatic secondary diaminechain extenders, and also by limiting the amount of reactive alkoxsilanegroups on the polymers. The N-substituted urea linkages formed duringreaction of these chain extenders with isocyanates provides for greaterflexibility than if forming non-N-substituted ureas. The N-substitutedgroup on the urea causes steric interactions within the linkage, andthese interactions are minimized by the N-substituted group rotatingslightly out of plane. N-substituted urea linkages, as opposed tonon-N-substituted, also provide for polymers with reduced viscosity dueto less inter- and intra-molecular hydrogen bonding between ureas. Thisin turn allows for polymers with reduced solvent content, and hencehigher solids content, to be synthesized. The use of N-substituted ureapolymers also allow for single-component coatings with lower volatileorganic compounds (VOCs) to be formulated. All newly formed urealinkages within the polymers are N-substituted, including those locatednear the terminal alkoxysilane groups.

The fast tack-free times for the herein single-component coatings areachieved by using N-substituted urea polymers with extended chains andterminal alkoxysilanes that possess glass transition temperatures nearor above room temperature. These glass transition temperatures resultfrom addition of the secondary diamine chain extenders during polymersynthesis, which forms larger molecules, such as dimers and trimers, andthus increases the overall molecular weight of the polymer. The fastdry-through times for the coatings are due to the fast curing nature ofthe terminal alkoxysilane groups on the polymers. The terminalalkoxysilane groups are located near N-substituted urea linkages, andwill react more rapidly with moisture than if non-N-substituted linkageswere used, such as in the case of acrylic-silane polymers.

The gloss retention of the herein single-component coatings are improvedby reducing the amount of moisture-curable alkoxysilane groups withinthe coating. Alkoxysilane groups within moisture-curable coatings areknown to post-cure slowly for weeks, and even months, after the coatingshave cured, and this is especially true in high humidity environments.As post-curing occurs over time, the gloss level of a moisture-curablecoating can decrease, and may no longer provide the same appearance.This is especially important for military-specified coatings, such asthe semi-gloss topside coatings used on Navy surface ships. Thus, bylimiting the amount of terminal alkoxysilane groups on the N-substitutedurea polymers, single-component coatings can be formulated wherepost-curing is minimized.

Adhesion of the single-component coatings of the present invention toepoxy primers can be improved by utilizing various N-substituted groups,such as ester-containing aliphatics, that provide hydrogen bonding withthe underlying substrate.

In one embodiment of the present invention, a moisture-curablesingle-component coating comprises an N-substituted urea polymer withextended chains and terminal alkoxysilane groups, a catalyst and asolvent.

In a second embodiment, a moisture-curable single-component coatingcomprises an N-substituted urea polymer with extended chains andterminal alkoxysilane groups, a reactive diluent, a catalyst, a pigment,a filler, an additive, and a solvent.

In another embodiment, the N-substituted urea polymer with extendedchains and terminal alkoxysilane groups comprises an aliphaticpolyisocyanate, N-substituted amino-functional alkoxysilanes, and asecondary diamine chain extender.

In yet another embodiment, a method for producing a single-componentcoating composition comprises synthesizing an N-substituted urea polymerwith extended chains and terminal alkoxysilane groups by first reactingan aliphatic polyisocyanate with an N-substituted amino-functionalalkoxysilane, followed by reaction with a secondary diamine chainextender, such that no unreacted isocyanate remains, then mixing thesynthesized polymer with a reactive diluent, a pigment, a filler, asolvent, a catalyst, an additive, or a combination thereof.

It is understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.These and other features and advantages of the invention, as well as theinvention itself, will become better understood by reference to thefollowing detailed description, appended claims, and accompanyingdrawings, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structure of an N-substituted urea polymer with extendedchains and terminal alkoxysilanes that is synthesized using an aliphaticpolyisocyanate based on an HDI isocyanurate trimer,N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functionalalkoxysilane), andN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine(a cycloaliphatic secondary diamine chain extender).

FIG. 2 is a structure of an N-substituted urea polymer with extendedchains and terminal alkoxysilanes that is synthesized using an aliphaticpolyisocyanate based on an HDI isocyanurate trimer, a Michael Additionadduct of butyl acrylate and 3-aminopropyltrimethoxysilane (anN-substituted amino-functional alkoxysilane), andN¹,N³-diethylpropane-1,3-diamine (an aliphatic secondary diamine chainextender).

FIG. 3 is a structure of an N-substituted urea polymer with extendedchains and terminal alkoxysilanes that is synthesized using a 1:1mixture of an aliphatic polyisocyanate based on an HDI isocyanuratetrimer and an aliphatic polyisocyanate based on a uretdione,N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functionalalkoxysilane), and N¹,N⁶-dimethylhexane-1,6-diamine (an aliphaticsecondary diamine chain extender).

FIG. 4 is a structure of an N-substituted urea polymer with extendedchains and terminal alkoxysilanes that is synthesized using an aliphaticpolyisocyanate based on a uretdione,N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functionalalkoxysilane), and a 1:1 mixture of N¹,N⁶-dimethylhexane-1,6-diamine (analiphatic secondary diamine chain extender) andN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine(a cycloaliphatic secondary diamine chain extender).

DETAILED DESCRIPTION OF THE INVENTION

References will now be made in detail to the preferred embodiments ofthe present invention, examples of which are illustrated in theaccompanying figures.

A single-component coating means that all components are pre-mixed anddoes not require the addition of additives, a catalyst or reactivecomponents before being applied to a substrate. The coating may need tobe shaken or stirred before use, but the entire product is containedwithin a single can or container. A single-component coating isconsidered “user friendly” because it can be easily applied to asubstrate, then restored simply by closing the container.Single-component coatings generate less waste than two-componentcoatings, because only the material removed from the can is utilized,unlike two-component coatings where the mixed materials will solidifyand become waste if not utilized. The term “single-component” coating isoften referred to as “1K”, which is an abbreviation for 1 Komponent (theGerman spelling of component). However, “1K” is not intended to meanthat the coating is made from a single chemical or substance, but ratherthat the end product does not need to be mixed with another componentbefore application to a substrate.

An exemplary single-component coating composition of the presentinvention comprises an N-substituted urea polymer with extended chainsand terminal alkoxysilanes, where the polymer is formed from analiphatic polyisocyanate, N-substituted amino-functional alkoxysilanes,and a secondary diamine chain extender, such that no free isocyanategroups remain. The polymer has an N-substituted group at all urealinkages that are formed during the reaction process. The alkoxysilanegroups are located at the terminus of the polymer, and the chainextenders are located internally. The single-component coatingcomposition can also comprise a reactive diluent, a solvent, a catalyst,a pigment, a filler, an additive, or a mixture thereof.

The N-substituted urea polymer with extended chains and terminalalkoxysilanes is the reaction product of an aliphatic polyisocyanate,N-substituted amino-functional alkoxysilanes, and a secondary diaminechain extender. The aliphatic isocyanate should have at least 2isocyanate (NCO) reactive groups per molecule. The aliphatic isocyanateis first reacted with an N-substituted amino-functional alkoxysilane togenerate N-substituted urea linkages and terminal alkoxysilane groups.The secondary diamine chain extender is then reacted with the remainingisocyanate groups. Reaction of the secondary diamine chain extender withthe isocyanate groups generates N-substitute urea linkages, while alsoincreasing the size of the resulting polymer and forming dimers,trimers, tetramers, etc. The polymer should contain no unreactedisocyanate groups once the reaction is finished. The polymer can besynthesized in a solvent or combination of solvents.

In an exemplary embodiment, the aforementioned polymer is formed byreacting 30-95% of the isocyanate groups on the aliphatic polyisocyanatewith an N-substituted amino-functional alkoxysilane, and 5-70% of theisocyanate groups on the aliphatic polyisocyanate with a secondarydiamine chain extender, such that no unreacted isocyanate remains in thepolymer. Addition of the chain extender forms larger molecules (e.g,dimers, trimers), which increases the overall molecular weight of thepolymer.

The aliphatic polyisocyanate can be aliphatic or cycloaliphatic.Aliphatic polyisocyanates are more weatherable (exterior durable) thanaromatic polyisocyanates, thereby providing greater color stability whenutilized for exterior coatings. Aliphatic polyisocyanates can havevarious numbers of reactive isocyanate (NCO) groups per molecule,depending on their structure. Typically, the number ranges from 2.5 to5.5. For the present invention, the aliphatic polyisocyanate should havegreater than 2 NCO groups per molecule. Suitable aliphaticpolyisocyanates include, but are not limited to, structures based onisocyanurates (e.g., HDI and IPDI trimers), biurets, uretdiones,allophanates, oxadiazinetriones, iminooxadiazinedione, and prepolymerscontaining urethanes. Mixtures of these isocyanates can also be used.There are many commercially available aliphatic polyisocyanates.

The N-substituted amino-functional alkoxysilane can be N-substituted3-aminopropyltrialkoxysilane, N-substituted3-aminopropylalkyldialkoxysilane or N-substituted dialkylalkoxysilane,where the alkyl group attached to the silicon atom can be methyl orethyl, and the alkoxy group attached to the silicon atom can be methoxy,ethoxy, n-propoxy or n-butoxy.

The N-substituted group of the amino-functional alkoxysilane can beC1-C12 alkyl or cycloalkyl. Examples include, but are not limited to,N-methyl-3-aminopropyltrimethoxysilane,N-ethyl-3-aminopropyltriethoxysilane,N-methyl-3-aminopropyltributoxysilane,N-ethyl-3-aminopropyltripropoxysilane,N-iso-propyl-3-aminopropyltrimethoxysilane,N-tert-butyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropylmethyldimethoxysilane,N-butyl-3-aminopropyldimethylmethoxysilane,N-butyl-3-aminopropyltriethoxysilane,N-butyl-3-aminopropyltripropoxysilane,N-butyl-3-aminopropyltributoxysilane,N-iso-butyl-3-aminopropyltrimethoxysilane,N-cyclohexyl-3-aminopropyltrimethoxysilane,N-hexyl-3-aminopropyltrimethoxysilane,N-nonyl-3-aminopropytrimethoxysilane andN-dodecyl-3-aminopropyltrimethoxysilane. Many of these are commerciallyavailable.

The N-substituted group of the amino-functional alkoxysilane can also bean ester-containing aliphatic or ester-containing fluorinated aliphatic,which are formed by the Michael Addition (conjugate addition) reactionbetween a molecule with a reactive “ene” group, such as an acrylate, and3-aminopropyltrialkoxysilane, 3-aminopropylalkyldialkoxysilane or3-aminopropyldialkylalkoxysilane. Conditions for forming MichaelAddition adducts with an amine are well known in the literature.Suitable acrylates include, but are not limited to, methyl acrylate,ethyl acrylate, butyl acrylate, cyclohexyl acrylate, hexyl acrylate,2-ethylhexyl acrylate, octyl acrylate, 4-tert-butylcyclohexyl acrylate,diethyl maleate, dimethyl maleate, dibutyl maleate, ethylene glycolmethyl ether acrylate, 1,1,1,3,3,3-hexafluoroisopropyl acrylate,2,2,2-trifluoroethyl acrylate and3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate. Examples include,but are not limited to, methyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, butyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 2-ethylhexyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, octyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 3,3,3-trifluoropropyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, dimethyl(3-(trimethoxysilyl)propyl)aspartate and diethyl(3-(trimethoxysilyl)propyl)aspartate.

The N-substituted group of the amino-functional alkoxysilane can also bean amide-containing aliphatic, which is formed by the Michael Addition(conjugate addition) reaction between a molecule with a reactive “ene”group, such as an acrylamide, and 3-aminopropyltrialkoxysilane,3-aminopropylalkyldialkoxysilane or 3-aminopropyldialkylalkoxysilane.Suitable acrylamides include, but are not limited to, N-ethylacrylamide,N-propylacrylamide, N-tert-butylacrylamide, N-cyclohexylacrylamide,N-ethyl maleimide and N,N′-diethylmaleamide. Examples include, but arenot limited to,N-propyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide,N-butyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide,N-cyclohexyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide and1-ethyl-3-((3-(trimethoxysilyl)propyl)amino)pyrrolidine-2,5-dione.

The secondary diamine chain extender is a molecule that contains tworeactive secondary amine groups, or N-substituted groups, with a chainof atoms between. These secondary diamine chain extenders are used forreacting with the isocyanate groups, extending the chain length betweenthe terminal alkoxysilanes, and increasing the overall molecular weightof the N-substituted urea polymer. The secondary diamines formN-substituted urea linkages once reacted with the isocyanate groups. Thesecondary diamine chain extenders provide increased flexibility,exterior durability, and faster tack-free times for the N-substitutedurea polymer and subsequent single-component coating. A mixture ofsecondary diamine chain extenders can be used to provide tailoredflexibility and hardness. The secondary diamine chain extender can be analiphatic or cycloaliphatic chain with secondary diamines, such as abis(secondary diamine). The secondary diamine chain extender can alsobe, but is not limited to, a dimethylpolysiloxane chain with secondarydiamines, a methylphenylpolysiloxane chain with secondary diamines, apolyether chain with secondary diamines, a polysulfide chain withsecondary diamines, or a mixture thereof.

The N-substituted groups of the secondary diamines can be C1-C12 alkyl,cycloalkyl or ester-containing aliphatic. The N-substituted groups canbe produced by reacting an amine with an aldehyde or ketone (e.g.,acetone, methylethylketone) then reducing (hydrogenating). TheN-substituted groups can also be produced by reacting an amine with amolecule containing a reactive “ene” group, such as an acrylate ormaleate, via a Michael Addition (conjugate addition) reaction. Suitablesecondary diamine chain extenders include, but are not limited to, thefollowing:

Structure Name

N¹,N³-dimethylpropane-1,3-diamine

N¹,N³-diethylpropane-1,3-diamine

N¹,N⁵-diisopropyl-2-methylpentane-1,5- diamine

N¹,N⁶-dimethylhexane-1,6-diamine

N¹,N⁶-bis(3,3-dimethylbutan-2-yl)hexane-1,6- diamine

N,3,3,5-tetramethyl-5- ((methylamino)methyl)cyclohexan-1-amine

N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine

tetraethyl 2,2′-((2-methylpentane-1,5- diyl)bis(azanediyl))disuccinate

4,4′-methylenebis(N-isopropylcyclohexan-1- amine)

tetraethyl 2,2′-((methylenebis(cyclohexane-4,1-diyl))bis(azanediyl))disuccinate

4,4′-methylenebis(N-(sec-butyl)cyclohexan-1- amine)

dibutyl 3,3′-(hexane-1,6- diylbis(azanediyl))dipropionate

3,3′-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis(N-methylpropan-1-amine)

N,N′-isopropylaminopropyl terminated polydimethylsiloxane

N,N′-ethylaminoisobutyl terminated polydimethylsiloxane

Several secondary diamine chain extenders are commercially available.

A person skilled in the art understands that secondary triamines,secondary tetramines, secondary pentaamines, or larger, could also beutilized as the chain extender, although the viscosity of the resultingN-substituted urea polymer would be greater than if using a similarsecondary diamine.

The N-substituted urea polymer with extended chains and terminalalkoxysilanes is the reaction product of an aliphatic polyisocyanate, anN-substituted amino-functional alkoxysilane, and a secondary diaminechain extender. As discussed above, numerous aliphatic polyisocyanates,secondary diamine chain extenders and N-substituted amino-functionalalkoxysilanes can be utilized, thus providing the ability to generate alarge variety of polymers that possess differences in molecular weight,structure and properties (e.g., cure times, hardness, flexibility,solvent resistance and exterior weathering resistance). In an examplesynthesis of the N-substituted urea polymer with extended chains andterminal alkoxysilanes, the polymer is the reaction product of (i) analiphatic polyisocyanate with at least 2 isocyanate (NCO) reactivegroups per molecule, where (ii) 30-95% of the isocyanate groups arereacted with an N-substituted amino-functional alkoxysilane, and (iii)5-70% of the isocyanate groups are reacted with a secondary diaminechain extender, such that no unreacted isocycanate remains in saidpolymer. Preferably, the N-substituted urea polymer with extended chainsand terminal alkoxysilanes is the reaction product of (i) an aliphaticpolyisocyanate with at least 2 isocyanate (NCO) reactive groups permolecule, where (ii) 50-80% of the isocyanate groups are reacted with anN-substituted amino-functional alkoxysilane, and (iii) 20-50% of theisocyanate groups are reacted with a secondary diamine chain extender,such that no unreacted isocycanate remains in said polymer. Morepreferably, the N-substituted urea polymer with extended chains andterminal alkoxysilanes is the reaction product of (i) an aliphaticpolyisocyanate with at least 2 isocyanate (NCO) reactive groups permolecule, where (ii) 60-70% of the isocyanate groups are reacted with anN-substituted amino-functional alkoxysilane, and (iii) 30-40% of theisocyanate groups are reacted with a secondary diamine chain extender,such that no unreacted isocycanate remains in said polymer.

A person skilled in the art understands that a small amount ofisocyanate groups (e.g., 1-5%) could remain unreacted in the polymer,and thereby could be used to assist with adhesion to a substrate, orcould be used to react with an isocyanate-reactive material that is notdiscussed in this invention. However, reacting a small percentage of theisocyanate groups on a polymer with a non-disclosed material is notexpected to change the properties of the polymer, and should not beconsidered a separate invention. For the purpose of makingisocyanate-free coatings, it is recommended that all isocyanate groupsbe reacted during synthesis of the N-substituted urea polymer.

The structure in FIG. 1 is an example of an N-substituted urea polymerwith extended chains and terminal alkoxysilanes that is synthesizedusing an aliphatic polyisocyanate based on an HDI isocyanurate trimer,N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functionalalkoxysilane), andN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine(a cycloaliphatic secondary diamine chain extender). In this example,all newly formed N-substituted urea groups possess either a butyl orisopropyl group.

Alternative structures of N-substituted urea polymers with extendedchains and terminal alkoxysilanes can be formed by varying the type ofaliphatic polyisocyanate, N-substituted amino-functional alkoxysilane,or the secondary diamine chain extender utilized in the syntheticprocess.

The structure in FIG. 2 is an example of an N-substituted urea polymerwith extended chains and terminal alkoxysilanes that is synthesizedusing an aliphatic polyisocyanate based on an HDI isocyanurate trimer, aMichael Addition adduct of butyl acrylate and3-aminopropyltrimethoxysilane (an N-substituted amino-functionalalkoxysilane), and N¹,N³-diethylpropane-1,3-diamine (an aliphaticsecondary diamine chain extender). This polymer demonstrated improvedadhesion to certain epoxy primers due to the increased hydrogen bondingthat the butyl-ester groups provide.

Alternative structures of N-substituted urea polymers with extendedchains and terminal alkoxysilanes can be formed by utilizing a mixtureof two different aliphatic isocyanates, an N-substitutedamino-functional alkoxysilane, and a secondary diamine chain extender.

The structure in FIG. 3 is an example of an N-substituted urea polymerwith extended chains and terminal alkoxysilanes that is synthesizedusing a 1:1 mixture of an aliphatic polyisocyanate based on an HDIisocyanurate trimer and an aliphatic polyisocyanate based on auretdione, N-butyl-3-aminopropyltrimethoxysilane (an N-substitutedamino-functional alkoxysilane), and N¹,N⁶-dimethylhexane-1,6-diamine (analiphatic secondary diamine chain extender). The N-substitutedamino-functional alkoxysilane is reacted with ˜60% of the isocyanategroups, whereas the secondary diamine chain extender is reacted with˜40% of the isocyanate groups. The structure is asymmetric due to theuse of two different aliphatic polyisocyanates.

The structure in FIG. 4 is an example of an N-substituted urea polymerwith extended chains and terminal alkoxysilanes that is synthesizedusing an aliphatic polyisocyanate based on a uretdione,N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functionalalkoxysilane), and a 1:1 mixture of N¹,N⁶-dimethylhexane-1,6-diamine (analiphatic secondary diamine chain extender) andN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine(a cycloaliphatic secondary diamine chain extender). The N-substitutedamino-functional alkoxysilane is reacted with ˜50% of the isocyanategroups, whereas the secondary diamine chain extenders are reacted with˜50% of the isocyanate groups. The structure is asymmetric due to theuse of two different secondary diamine chain extenders. The reason forthe use of two different chain extenders is to provide tailoredproperties of both hardness and flexibility.

Properties of the synthesized polymers were evaluated by applying thepolymer solutions to tinplate panels or Laneta cards at 2 to 6 mils(50.8 to 152.4 microns) wet film thickness. The resulting dry filmthickness of each film (a clear coating) depended on the percentagevolume solids of the polymer solution. In general, and without using acatalyst, the N-substituted urea polymers with extended chains andterminal alkoxysilanes have tack-free times of only a few hours. This isdue to the polymers having glass transition temperatures near or aboveroom temperature. After 7 days of curing at ambient conditions, theclear coatings demonstrate a resistance of 50-100 double rubs to methylethyl ketone (MEK) solvent. Furthermore, when tested for flexibility,the clear coatings pass a 180 degree bend test and a ¼″ Mandrel Bendtest without cracking. The coatings could also be straightened and bentnumerous times without damage. Addition of only 1 weight % of acatalyst, based on polymer solids, provided clear coatings withdry-through times of 3-6 hours and a solvent resistance of >100 MEKdouble rubs. The flexibility was unaffected by addition of a catalyst.

The N-substituted urea polymers with extended chains and terminalalkoxysilanes are used to formulate both clear and pigmentedsingle-component coatings. The single-component coatings can alsocomprise a reactive diluent, a filler, a pigment, a solvent, anadditive, a catalyst, or a mixture thereof.

A reactive diluent may be used for modifying the properties of thesingle-component coating, such as increasing the flexibility orhardness, reducing solvent content and viscosity, or increasingresistance to exterior degradation from sunlight. The reactive diluentcan be a polysiloxane with at least 2 hydrolyzable alkoxysilane groups,such as, but not limited to, poly(dimethoxysiloxane),poly(diethoxysiloxane), methoxy-functional dimethylpolysiloxane,methoxy-functional methylphenylpolysiloxane, ethoxy-functionaldimethylpolysiloxane, and structures based on tetraethyl orthosilicate.The reactive diluent can also be hydroxyl-functional versions (viahydrolysis) of these polysiloxanes. Many of these are commerciallyavailable.

The reactive diluent can also be an alkyl-functional alkoxysilane, wherethe alkyl group is C1-C16 alkyl, cycloalkyl or fluorinated alkyl, andthe alkoxysilane group is trimethoxysilane, triethoxysilane,methyldimethoxysilane, methyldiethoxysilane, dimethylmethoxysilane anddimethylethoxysilane. Examples include, but are not limited to,propyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane,octyltriethoxysilane, hexadecyltrimethoxysilane,cyclohexyltriethoxysilane and 1H,1H,2H,2H-perfluorooctyltriethoxysilane.

The reactive diluent can also be a polysiloxane-urea polymer withhydrolysable alkoxysilane groups. These reactive diluents are formed byreacting a polysiloxane with primary diamines or a polysiloxane withsecondary diamines with 3-isocyanatopropyltrimethoxysilane or3-isocyanatotriethoxysilane. They can also be formed by reacting adiisocyanate-functional polysiloxane with an N-substituted3-aminopropylalkoxysilane. The polysiloxane can be adimethylpolysiloxane or methylphenylpolysiloxane. The N-substitutedgroups of the secondary diamines (attached to the polysiloxane) andN-substituted 3-aminopropylalkoxysilane can be C1-C12 alkyl, cycloalkylor ester-containing aliphatic. The alkoxysilane group of theN-substituted 3-aminopropylalkoxysilane can be trimethoxysilane,triethoxysilane, methyldimethoxysilane, methyldiethoxysilane,dimethylmethoxysilane and dimethylethoxysilane. There are severalcommercial sources of the raw materials for synthesizing these reactivediluents. Example structures of these synthesized reactive diluentsinclude, but are not limited to, the following:

Structure Name

Bis((3- triethoxysilyl)propyl)urea adduct based on N,N′-ethylaminoisobutyl terminated polydimethylsiloxane

Bis((3- triethoxysilyl)propyl)urea adduct based on aminopropylterminated polydimethylsiloxane

Bis(N-substituted 3-aminopropylalkoxysilane) urea adduct based ondiisocyanate-functional polydimethylsiloxane

Reactive diluents that contain N-substituted urea groups are used due totheir reduced hydrogen bonding character, lower viscosity and reducedsolvent requirements.

The reactive diluent can also be an aliphatic or cycloaliphaticN-substituted urea with hydrolysable alkoxysilane groups. These reactivediluents are formed by reacting an aliphatic or cycloaliphatic secondarydiamine chain extender with 3-isocyanatopropyltrimethoxysilane or3-isocyanatotriethoxysilane. The 3-isocyanatopropyltrimethoxysilane and3-isocyanatotriethoxysilane are commercially available. Suitablesecondary diamine chain extenders are the same as those utilized forsynthesizing the N-substituted urea polymer with extended chains andterminal alkoxysilanes. Example structures of these synthesized reactivediluents include, but are not limited to, the following:

Structure Name

1,1′-(hexane-1,6-diyl)bis(1- (3,3-dimethylbutan-2-yl)-3- (3-(triethoxysilyl)propyl)urea)

1-isopropyl-1-((5-(1- isopropyl-3-(3- (triethoxysilyl)propyl)ureido)-1,3,3- trimethylcyclohexyl)methyl)- 3-(3- (triethoxysilyl)propyl)urea

1,1′-(hexane-1,6-diyl)bis(1- methyl-3-(3- (triethoxysilyl)propyl)urea)

tetraethyl 2,2′-4,4,22,22- tetraethoxy-12-methyl- 9,17-dioxo-3,23-dioxa-8,10,16,18-tetraaza-4,22- disilapentacosane-10,16- diyl)disuccinate

The reactive diluent can also be a polyester-urethane polymer withhydrolyzable alkoxysilane groups. These reactive diluents are formed byreacting an aliphatic or cycloaliphatic polyester polyol with3-isocyanatopropyltrimethoxysilane or 3-isocyanatotriethoxysilane. Thepolyester polyol should be linear or slightly branched, and is utilizedto provide increased flexibility for the single-component coating.Suitable polyester polyols are commercially available. The3-isocyanatopropyltrimethoxysilane and 3-isocyanatotriethoxysilane arealso commercially available.

Suitable solvents for synthesis of the N-substituted urea polymer withextended chains and terminal alkoxysilane groups are those that are notreactive with isocyanate groups. These solvents include, but are notlimited to, xylenes, light aromatic naphtha, mineral spirits, butylacetate, 1-methoxy-2-propyl acetate, tert-butyl acetate, butylpropionate, pentyl propionate, ethyl 3-ethoxypropionate,parachlorobenzotrifluoride, tetrahydrofuran, 1,4-dioxane,dimethylacetamide and N-methyl pyrrolidone. These solvents can also beutilized in single-component coating compositions.

A catalyst is used to accelerate the rate of hydrolysis of the terminalalkoxysilane groups on the N-substituted urea polymer with extendedchains, and to facilitate crosslinking of the resulting silanol groupsto form a cured coating. Suitable catalyst for the single-componentcoating composition include, but are not limited to, organic tincompounds, such as dibutyl tin dilaurate, dibutyl tin diacetate anddibutyl tin bis(2-ethylhexoate), metal alkoxides, such as titaniumtetraisopropoxide, aluminum triethoxide and zirconium tetrabutoxide,alkalines, such as potassium hydroxide, organic acids, inorganic acids,tertiary amines, or mixtures thereof. A catalyst can be used in a clearor pigmented single-component coating.

Suitable pigments for the single-component coating composition include,but are not limited to, titanium dioxide, carbon black, red iron oxide,yellow iron oxide, copper phthalocyanine blue, sodium aluminumsulphosilicate, chromium oxide, cobalt chromite green spinel, chromiumgreen-black hematite, nickel antimony titanium yellow rutile, andmanganese-based pigments.

Suitable fillers for the single-component coating composition include,but are not limited to, amorphous silica, functionalized silica, talc,mica, wollastonite, calcium carbonate, glass beads, graphite, polymericwaxes, acrylic beads, polyurethane beads and ceramic microspheres.

Suitable additives for the single-component coating composition include,but are not limited to, rheology modifiers, thickening agents, adhesionpromoters, reinforcing agents, wetting and dispersing agents,anti-floating agents, flame retardants, ultraviolet (UV) absorbers,hindered amine light stabilizers (HALS), and flow and leveling agents.

Depending on the level of catalyst and type of fillers, thesingle-component coating compositions have a pot-life of 6-12 months ina closed can and in the absence of moisture.

The single-component coating composition can be applied via spray, brushor roll application. The single-component coating can be applied at 1 to12 mils (25.4 to 304.8 microns) wet film thickness, preferably 3 to 10mils (76.2 to 254 microns) wet film thickness, and more preferably 4 to6 mils (101.6 to 152.4 microns) wet film thickness. Viscosities aretypically within the range of HVLP to pressure-pot sprayable, dependingon the composition.

The single-component coating can be applied to a variety of substrates.Suitable substrates include, but are not limited to, epoxy primedsurfaces, polyurethane primed surfaces, pretreatments, epoxy-basedcomposites, weathered or abraded silicone alkyd coatings, weathered orabraded polysiloxane coatings, bare steel surfaces, bare aluminumsurfaces, bare aluminum alloy surfaces, concrete, glass, ceramics andplastics.

EXAMPLES

The following examples describe the synthesis of N-substituted ureapolymers with extended chains and terminal alkoxysilanes, in addition tosingle-component coating compositions that are based on the polymers.The examples are not to be considered as limiting the invention to theirdetails.

Example 1

This example describes the preparation of a polymer based on analiphatic polyisocyanate, N-alkyl amino-functional alkoxysilanes, and acycloaliphatic secondary diamine chain extender with N-alkyl groups. Thestructure is shown in FIG. 1.

81.6 g (0.446 equiv.) of an aliphatic polyisocyanate based on an HDIisocyanurate trimer (commercially available as Desmodur N-3600 fromBayer Material Science) was dissolved in 115 g of Aromatic 100(commercially available from Exxon) in a 500 ml 3-neck round bottomflask equipped with an Argon inlet and thermometer. This was followed bythe addition of 5 g of vinyltrimethoxysilane (commercially availablefrom Aldrich) as a drying agent. Using an addition funnel, 71.38 g(0.303 equiv.) of N-butyl-3-aminopropyltrimethoxysilane (commerciallyavailable as SIB 1932.2 from Gelest) was added dropwise to the solutionwhile keeping the temperature at 40-50° C. Next, 18.78 g (0.147 equiv.)of N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexanaminewas added dropwise while continuing to keep the temperature at 40-50° C.After the addition was complete, the solution was stirred for anadditional 15-30 minutes until the infrared (IR) spectra indicated thatno more free isocyanate (NCO) (2270 cm⁻¹) remained in solution. Thepolymer solution was calculated to have a solids content of 60.6% byweight.

Example 2

A semi-gloss single-component coating composition was prepared by mixing165.01 g of the polymer solution (100 g solid polymer by weight) inExample 1 with 11.65 g titanium dioxide, 2.9 g Shepherd Black 30C940,1.95 g Shepherd Green 410, 1.0 g Shepherd Yellow 30C119, 20 g ceramicmicrospheres, 10 g Oxsol 100 and 0.5 g dibutyl tin dilaurate.

The coating was applied at 3 mils (76.2 microns) wet film thickness totinplate panels and a laneta card, and was allowed to cure (crosslink)at ambient conditions (77° F. and 50% relative humidity). The coatingdemonstrated a tack-free time of 1 hour and a dry-hard time of 6 hours.After 14 days of curing at ambient conditions, the coating demonstrateda 60° gloss of 57 GU, a resistance of 100+ double rubs to methyl ethylketone (MEK) solvent, and a pendulum hardness of 84 oscillations. Thecoating also demonstrated high flexibility, and passed a 180 degree bendtest and a ¼″ Mandrel Bend test without cracking.

Example 3

A semi-gloss single-component coating composition was prepared by mixing132.01 g of the polymer solution (80 g solid polymer by weight) inExample 1 with 11.65 g titanium dioxide, 2.9 g Shepherd Black 30C940,1.95 g Shepherd Green 410, 1.0 g Shepherd Yellow 30C119, 30 g ceramicmicrospheres, 20 g of a methoxy-functional dimethylpolysiloxane(commercially available as Silres SY231 from Wacker Chemical), 15 gOxsol 100 and 1.0 g dibutyl tin dilaurate.

The coating was applied at 3 mils (76.2 microns) wet film thickness totinplate panels and a laneta card, and was allowed to cure (crosslink)at ambient conditions (77° F. and 50% relative humidity). The coatingdemonstrated a tack-free time of 1 hour and a dry-hard time of 3 hours.After 14 days of curing at ambient conditions, the coating demonstrateda 60° gloss of 48 GU, a resistance of 100+ double rubs to methyl ethylketone (MEK) solvent, and a pendulum hardness of 91 oscillations. Thecoating also demonstrated high flexibility, and passed a 180 degree bendtest and a ¼″ Mandrel Bend test without cracking. Xenon ArcWeatherometer (WOM) testing of the coating demonstrated a color change(Delta E) of <0.5 after 2000 hours exposure.

Example 4

This example describes the preparation of a polymer based on analiphatic polyisocyanate, N-substituted amino-functional alkoxysilaneswith butyl ester-containing groups, and an aliphatic secondary diaminechain extender with N-alkyl groups. The structure is shown in FIG. 2.

35.5 g (0.194 equiv.) of an aliphatic polyisocyanate based on an HDIisocyanurate trimer (commercially available as Desmodur N-3600 fromBayer Material Science) was dissolved in 60 g of Aromatic 100 solvent(commercially available from Exxon) in a 500 ml 3-neck round bottomflask equipped with an Argon inlet and thermometer. This was followed bythe addition of 2 g of vinyltrimethoxysilane (commercially availablefrom Aldrich) as a drying agent. Using an addition funnel, 40 g (0.130equiv.) of butyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate(synthesized by reacting 3-aminopropyltrimethoxysilane with butylacrylate via a Michael Addition reaction) was added dropwise to thesolution while keeping the temperature at 40-50° C. Next, 4.17 g (0.064equiv.) of N¹,N³-diethylpropane-1,3-diamine was added dropwise whilecontinuing to keep the temperature at 40-50° C. After the addition wascomplete, the solution was stirred for an additional 15-30 minutes untilthe infrared (IR) spectra indicated that no more free isocyanate (NCO)(2270 cm⁻¹) remained in solution. The polymer solution was calculated tohave a solids content of 57.6% by weight.

Example 5

This example describes the preparation of a polymer based on analiphatic polyisocyanate, N-alkyl amino-functional alkoxysilanes, and acycloaliphatic secondary diamine chain extender with N-alkyl groups,although with different ratios than utilized in Example 1.

81.6 g (0.446 equiv.) of an aliphatic polyisocyanate based on an HDIisocyanurate trimer (commercially available as Desmodur N-3600 fromBayer Material Science) was dissolved in 115 g of xylenes (commerciallyavailable from Aldrich) in a 500 ml 3-neck round bottom flask equippedwith an Argon inlet and thermometer. This was followed by the additionof 5 g of vinyltrimethoxysilane (commercially available from Aldrich) asa drying agent. Using an addition funnel, 84.03 g (0.357 equiv.) ofN-butyl-3-aminopropyltrimethoxysilane (commercially available as SIB1932.2 from Gelest) was added dropwise to the solution while keeping thetemperature at 40-50° C. Next, 12.57 g (0.0979 equiv.) ofN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexanaminewas added dropwise while continuing to keep the temperature at 40-50° C.After the addition was complete, the solution was stirred for anadditional 15-30 minutes until the infrared (IR) spectra indicated thatno more free isocyanate (NCO) (2270 cm⁻¹) remained in solution. Thepolymer solution was calculated to have a solids content of 61.4% byweight.

Example 6

A semi-gloss single-component coating composition was prepared by mixing130.29 g of the polymer solution (80 g solid polymer by weight) inExample 5 with 11.65 g titanium dioxide, 2.9 g Shepherd Black 30C940,1.95 g Shepherd Green 410, 1.0 g Shepherd Yellow 30C119, 30 g ceramicmicrospheres, 20 g of a methoxy-functional dimethylpolysiloxane(commercially available as Silres SY231 from Wacker Chemical), 5 g Oxsol100 and 1.0 g dibutyl tin dilaurate.

The coating was applied at 3 mils (76.2 microns) wet film thickness totinplate panels and a laneta card, and was allowed to cure (crosslink)at ambient conditions (77° F. and 50% relative humidity). The coatingdemonstrated a tack-free time of 3 hours and a dry-hard time of 6 hours.After 14 days of curing at ambient conditions, the coating demonstrateda 60° gloss of 48 GU, a resistance of 100+ double rubs to methyl ethylketone (MEK) solvent, and a pendulum hardness of 82 oscillations. Thecoating also demonstrated high flexibility, and passed a 180 degree bendtest and a ¼″ Mandrel Bend test without cracking. Xenon ArcWeatherometer (WOM) testing of the coating demonstrated a color change(Delta E) of <0.80 after 2000 hours exposure.

Example 7

A low-gloss single-component coating composition was prepared by mixing130.29 g of the polymer solution (80 g solid polymer by weight) inExample 5 with 15 g titanium dioxide, 0.2 g carbon black, 25 g amorphoussilica, 20 g of a methoxy-functional dimethylpolysiloxane (commerciallyavailable as Silres SY231 from Wacker Chemical), 30 g xylenes and 1.0 gdibutyl tin dilaurate.

The coating was applied at 3 mils (76.2 microns) wet film thickness totinplate panels and a laneta card, and was allowed to cure (crosslink)at ambient conditions (77° F. and 50% relative humidity). The coatingdemonstrated a tack-free time of 3 hours and a dry-hard time of 6 hours.After 14 days of curing at ambient conditions, the coating demonstrateda 60° gloss of 0.9 GU, a 85° gloss of 2.3 GU, a resistance of 100+double rubs to methyl ethyl ketone (MEK) solvent, and a pendulumhardness of 56 oscillations. The coating also demonstrated highflexibility, and passed a 1″ Mandrel Bend test without cracking.

The above descriptions are those of the preferred embodiments of theinvention. Various modifications and variations are possible in light ofthe above teachings without departing from the spirit and broaderaspects of the invention. It is therefore to be understood that theclaimed invention may be practiced otherwise than as specificallydescribed. Any references to claim elements in the singular, forexample, using the articles “a,” “an,” “the,” or “said,” is not to beconstrued as limiting the element to the singular.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. A single-component coating composition,comprising an N-substituted urea polymer with extended chains andterminal alkoxysilanes, wherein said polymer is a reaction product of analiphatic polyisocyanate, an N-substituted amino-functional alkoxysilanewith monovalent or divalent N-substituted groups, and a secondarydiamine chain extender with monovalent or divalent N-substituted groups,wherein no unreacted isocyanate remains in said polymer, and whereinsaid polymer possesses a molecular weight of less than 3000 when saidsecondary diamine chain extender comprises monovalent N-substitutedgroups.
 2. The composition of claim 1, additionally comprising acatalyst, a reactive diluent, a pigment, a filler, a solvent, anadditive, or any combination thereof.
 3. The composition of claim 1,wherein the N-substituted urea polymer with extended chains and terminalalkoxysilanes is a reaction product of: an aliphatic polyisocyanate withat least 2 isocyanate reactive groups per molecule; an N-substitutedamino-functional alkoxysilane, wherein 30 to 95% of the isocyanategroups are reacted with said N-substituted amino-functionalalkoxysilane; and a secondary diamine chain extender, wherein 5 to 70%of the isocyanate groups are reacted with said secondary diamine chainextender.
 4. The composition of claim 1, wherein the N-substituted ureapolymer with extended chains and terminal alkoxysilanes is a reactionproduct of: an aliphatic polyisocyanate with at least 2 isocyanatereactive groups per molecule; an N-substituted amino-functionalalkoxysilane, wherein 50 to 80%, and preferably 60 to 70%, of theisocyanate groups are reacted with said N-substituted amino-functionalalkoxysilane; and a secondary diamine chain extender, wherein 20 to 50%,and preferably 30 to 40%, of the isocyanate groups are reacted with saidsecondary diamine chain extender.
 5. The composition of claim 1, whereinthe aliphatic polyisocyanate is aliphatic or cycloaliphatic andcomprises isocyanurates, biurets, uretdiones, allophanates,oxadiazinetrione, iminooxadiazinediones, or any combination thereof. 6.The composition of claim 1, wherein the N-substituted amino-functionalalkoxysilane comprises N-substituted 3-aminopropyltrialkoxysilane,N-substituted 3-aminopropylalkyldialkoxysilane, N-substituted3-aminopropyldialkylalkoxysilane, or any combination thereof.
 7. Thecomposition of claim 1, wherein the N-substituted amino-functionalalkoxysilane comprises N-substituted groups that are C1-C12 alkyl,cycloalkyl, ester-containing aliphatic, ester-containing fluorinatedaliphatic, amide-containing aliphatic, or any combination thereof. 8.The composition of claim 1, wherein the N-substituted amino-functionalalkoxysilane comprises N-methyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropylmethyldimethoxysilane,N-butyl-3-aminopropyltriethoxysilane,N-cyclohexyl-3-aminopropyltrimethoxysilane, butyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 2-ethylhexyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 3,3,3-trifluoropropyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, dimethyl(3-(trimethoxysilyl)propyl)aspartate, diethyl(3-(trimethoxysilyl)propyl)aspartate,N-propyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide,1-ethyl-3-((3-(trimethoxysilyl)propyl)amino)pyrrolidine-2,5-dione, orany combination thereof.
 9. The composition of claim 1, wherein abackbone of the secondary diamine chain extender comprises polysiloxane.10. The composition of claim 1, wherein the secondary diamine chainextender comprises an aliphatic or cycloaliphatic chain with secondarydiamines.
 11. The composition of claim 1, wherein the secondary diaminechain extender comprises a dimethylpolysiloxane chain with secondarydiamines, a methylphenylpolysiloxane chain with secondary diamines, apolyether chain with secondary diamines, a polysulfide chain withsecondary diamines, or any combination thereof.
 12. The composition ofclaim 1, wherein the secondary diamine chain extender comprisesN-substituted groups that are C1-C12 alkyl, cycloalkyl, ester-containingaliphatic, or any combination thereof.
 13. The composition of claim 1,wherein the secondary diamine chain extender comprisesN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine,N¹,N⁶-bis(3,3-dimethylbutan-2-yl)hexane-1,6-diamine, tetraethyl2,2′-((2-methylpentane-1,5-diyl)bis(azanediyl))disuccinate, tetraethyl2,2′-((methylenebis(cyclohexane-4,1-diyl))bis(azanediyl))disuccinate,N¹,N³-diethylpropane-1,3-diamine, N¹,N⁶-dimethylhexane-1,6-diamine, orany combination thereof.
 14. The composition of claim 1, wherein 0 to100% of the solids content, by weight, is the N-substituted urea polymerwith extended chains and terminal alkoxysilanes.
 15. The composition ofclaim 1, wherein the N-substituted urea polymer with extended chains andterminal alkoxysilanes comprises 50 to 90% of the solids content, byweight, and a catalyst, a reactive diluent, a pigment, a filler, anadditive, or any combination thereof, comprises 10 to 50% of the solidscontent, by weight.
 16. A substrate coated with the single-componentcoating composition of claim
 1. 17. A method for making asingle-component coating composition, comprising: synthesizing anN-substituted urea polymer with extended chains and terminalalkoxysilanes from an aliphatic polyisocyanate; an N-substitutedamino-functional alkoxysilane with monovalent or divalent N-substitutedgroups; and a secondary diamine chain extender with monovalent ordivalent N-substituted groups, wherein the polymer possesses a molecularweight of less than 3000 when the secondary diamine chain extendercomprises monovalent N-substituted groups; and mixing the synthesizedpolymer with a catalyst, a reactive diluent, a pigment, a filler, asolvent, an additive, or any combination thereof; wherein no unreactedisocyanate remains in the polymer.
 18. The method of claim 17, whereinthe N-substituted urea polymer with extended chains and terminalalkoxysilanes is a reaction product of: an aliphatic polyisocyanate withat least 2 isocyanate reactive groups per molecule; an N-substitutedamino-functional alkoxysilane, wherein 30 to 95% of the isocyanategroups are reacted with said N-substituted amino-functionalalkoxysilane; and a secondary diamine chain extender, wherein 5 to 70%of the isocyanate groups are reacted with said secondary diamine chainextender.
 19. The method of claim 17, wherein the N-substituted ureapolymer with extended chains and terminal alkoxysilanes is a reactionproduct of: an aliphatic polyisocyanate with at least 2 isocyanatereactive groups per molecule; an N-substituted amino-functionalalkoxysilane, wherein 50 to 80%, and preferably 60 to 70%, of theisocyanate groups are reacted with said N-substituted amino-functionalalkoxysilane; and a secondary diamine chain extender, wherein 20 to 50%,and preferably 30 to 40%, of the isocyanate groups are reacted with saidsecondary diamine chain extender.
 20. The method of claim 17, whereinthe aliphatic polyisocyanate is aliphatic or cycloaliphatic andcomprises isocyanurates, biurets, uretdiones, allophanates,oxadiazinetrione iminooxadiazinediones, or any combination thereof. 21.The method of claim 17, wherein the N-substituted amino-functionalalkoxysilane comprises N-methyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropylmethyldimethoxysilane,N-butyl-3-aminopropyltriethoxysilane,N-cyclohexyl-3-aminopropyltrimethoxysilane, butyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 2-ethylhexyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 3,3,3-trifluoropropyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, dimethyl(3-(trimethoxysilyl)propyl)aspartate, diethyl(3-(trimethoxysilyl)propyl)aspartate,N-propyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide,1-ethyl-3-((3-(trimethoxysilyl)propyl)amino)pyrrolidine-2,5-dione, orany combination thereof.
 22. The method of claim 17, wherein thesecondary diamine chain extender comprisesN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine,N¹,N⁶-bis(3,3-dimethylbutan-2-yl)hexane-1,6-diamine, tetraethyl2,2′-((2-methylpentane-1,5-diyl)bis(azanediyl))disuccinate, tetraethyl2,2′-((methylenebis(cyclohexane-4,1-diyl))bis(azanediyl))disuccinate,N¹,N³-diethylpropane-1,3-diamine, N¹,N⁶-dimethylhexane-1,6-diamine, orany combination thereof.
 23. The method of claim 17, wherein 0 to 100%of the solids content, by weight, is the N-substituted urea polymer withextended chains and terminal alkoxysilanes.
 24. The method of claim 17,wherein the N-substituted urea polymer with extended chains and terminalalkoxysilanes comprises 50 to 90% of the solids content, by weight, anda catalyst, a reactive diluent, a pigment, a filler, an additive, or anycombination thereof, comprises 10 to 50% of the solids content, byweight.
 25. A substrate coated with the single-component coatingcomposition made by the method of claim
 17. 26. A single-componentcoating composition made by the method comprising: synthesizing anN-substituted urea polymer with extended chains and terminalalkoxysilanes from: an aliphatic polyisocyanate with at least 2isocyanate reactive groups per molecule; an N-substitutedamino-functional alkoxysilane; and a secondary diamine chain extender,wherein said aliphatic polyisocyanate and said N-substitutedamino-functional alkoxysilane are reacted together to form anisocyanate-terminated intermediate and then said isocyanate-terminatedintermediate is linked with said secondary diamine chain extender; andmixing the synthesized polymer with a catalyst, a reactive diluent, apigment, a filler, a solvent, an additive, or any combination thereof;wherein no unreacted isocyanate remains in the polymer.
 27. Thecomposition of claim 26, wherein the N-substituted urea polymer withextended chains and terminal alkoxysilanes is a reaction product of: analiphatic polyisocyanate with at least 2 isocyanate reactive groups permolecule; an N-substituted amino-functional alkoxysilane, wherein 30 to95% of the isocyanate groups are reacted with said N-substitutedamino-functional alkoxysilane; and a secondary diamine chain extender,wherein 5 to 70% of the isocyanate groups are reacted with saidsecondary diamine chain extender.
 28. The composition of claim 26,wherein the N-substituted urea polymer with extended chains and terminalalkoxysilanes is a reaction product of: an aliphatic polyisocyanate withat least 2 isocyanate reactive groups per molecule; an N-substitutedamino-functional alkoxysilane, wherein 50 to 80%, and preferably 60 to70%, of the isocyanate groups are reacted with said N-substitutedamino-functional alkoxysilane; and a secondary diamine chain extender,wherein 20 to 50%, and preferably 30 to 40%, of the isocyanate groupsare reacted with said secondary diamine chain extender.
 29. Thecomposition of claim 26, wherein the aliphatic polyisocyanate isaliphatic or cycloaliphatic and comprises isocyanurates, biurets,uretdiones, allophanates, oxadiazinetrione iminooxadiazinediones, or anycombination thereof.
 30. The composition of claim 26, wherein theN-substituted amino-functional alkoxysilane comprisesN-methyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropyltrimethoxysilane,N-butyl-3-aminopropylmethyldimethoxysilane,N-butyl-3-aminopropyltriethoxysilane,N-cyclohexyl-3-aminopropyltrimethoxysilane, butyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 2-ethylhexyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, 3,3,3-trifluoropropyl3-((3-(trimethoxysilyl)propyl)amino)propanoate, dimethyl(3-(trimethoxysilyl)propyl)aspartate, diethyl(3-(trimethoxysilyl)propyl)aspartate,N-propyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide,1-ethyl-3-((3-(trimethoxysilyl)propyl)amino)pyrrolidine-2,5-dione, orany combination thereof.
 31. The composition of claim 26, wherein thesecondary diamine chain extender comprisesN-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine,N¹,N⁶-bis(3,3-dimethylbutan-2-yl)hexane-1,6-diamine, tetraethyl2,2′-((2-methylpentane-1,5-diyl)bis(azanediyl))disuccinate, tetraethyl2,2′-((methylenebis(cyclohexane-4,1-diyl))bis(azanediyl))disuccinate,N¹,N³-diethylpropane-1,3-diamine, N¹,N⁶-dimethylhexane-1,6-diamine, orany combination thereof.